Killer virus here to stay, say experts

Washington: An alarming new respiratory disease that spread from southern China to virtually every continent within months is probably entrenched in the population, health experts said today.

World health officials moved quickly to try to contain the outbreak of Severe Acute Respiratory Syndrome once word got out, but it was carried too quickly by person-to-person contact and is now probably here to stay, they said.

The disease concerns doctors because it can cause severe pneumonia that cannot be helped by drugs. About four per cent of patients die.

There are more questions than answers right now about SARS because doctors are not 100 per cent certain about the virus that causes the disease and are still collecting data, said Dr Jim Hughes, head of infectious diseases at the US Centres for Disease Control and Prevention.

Once there is a test for the virus that causes the disease, doctors can find out how common it is, how infectious, and whether some people are more likely to spread it than others.

"We have more than 150 suspected SARS cases in the United States today. At the end of all this we'll be able to classify many of those into confirmed or not SARS categories," Hughes said in a telephone interview.

This compares to a minimum of 250,000 deaths a year globally from influenza and its complications, but doctors are not ready to dismiss SARS.

"I think we have to assume that the virus is in Asia to stay," Hughes said.

"In terms of its introduction into North America, whether it is here to stay I think remains to be seen - but I think we should assume that it may well be."

CDC director Dr Julie Gerberding earlier this week suggested SARS may begin to show a seasonal pattern, as do other respiratory diseases such as colds and influenza. Doctors believe a coronavirus similar to strains that cause the common cold may cause SARS.

"I think you might expect it will because other respiratory illnesses do," Hughes said.

Scientists are already working on a vaccine to fight SARS and are screening banks of drugs to see if one can fight the virus. But they have warned that it takes years to develop a new vaccine for a disease.

Vaccines and drugs are unlikely to wipe out any illness.

The only human disease that has been eradicated is smallpox, through a global immunisation program that ended in 1980.

WHO says it is close to eradicating polio, another viral disease that infects only humans, but says pockets remain in places such as Afghanistan and parts of Africa.

Despite years of work on flu vaccines, influenza manages to adapt and evolve and cause a new epidemic every year.

Hughes said it is only a matter of time before another influenza pandemic sweeps the world, killing perhaps millions.

In oterh developments today:

<li> Canadian health officials fighting the spread of the deadly SARS virus are taking no chances with quarantine breakers, shutting down two Toronto schools and sending about 200 workers at a Toronto company into quarantine.

Thousands of Canadians, mostly in the Toronto area, and many of them health care workers, have been quarantined in their homes amid fears that they have been exposed to the virus and might infect others.

<li> An American teacher who contracted SARS in China has died in Hong Kong on arrival at a hospital, reports and officials said. Hong Kong press identified the American as James Salisbury, 50, who had been teaching English in neighbouring Shenzhen.

Reports said Chinese authorities had refused repeated requests from friends asking for Salisbury to be treated in Hong Kong. He was confirmed dead on arrival at a Hong Kong hospital late yesterday after finally being transferred from a Shenzhen hospital with his six-year-old son, who has also been infected with the virus.

<li> Two more people have died of SARS in China and the number of cases has risen by 11 to 1,290, the health ministry said today. This brings to 55 the number who have died from atypical pneumonia on the mainland as of April 9.

The ministry said the new deaths were in southern Guangdong province, where SARS is believed to have originated, and in northern Shanxi province.